The Health Service Executive says it has seen 'very significant and worrying' Covid-19 trends emerge over the last 10 days.
The group is concerned by the increase in the number of confirmed cases reported over the last two weeks, increasingly steadily amid a marked decline in deaths.
Between July 5 and 18, there were 267 new cases, compared to 155 in the two weeks previous.
HSE CEO Paul Reid says another worrying trend relates to close contacts.
"Significantly, the close contacts have increased by over 55% in the last week.
"The number has risen from 2 to 5.4 for each case."
These fears have been voiced as the number of cases last night was 36, the highest one-day incidence of new cases in a month.